If two wagon body ends of a rail vehicle are supported on a common bogey, this is referred to as a Jakob's bogey. The individual vehicle units of the rail vehicle are connected in this case by what is referred to as a short coupling, which is generally released only for maintenance or repair purposes. Short couplings can be used for the semi-permanent connection of two or more vehicles and can be found, for example, in commuter trains. Short couplings are also used in goods traffic. At any rate, it is necessary for the articulated coupling to be movable in all three spatial directions.